KMSAN: uninit-value in gf128mul_4k_lle (3)

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit:    cddc52641fd2 kmsan: use __memmove() in fixup_bad_iret()
git tree:       https://github.com/google/kmsan.git/master
console output: https://syzkaller.appspot.com/x/log.txt?x=111c426d400000
kernel config:  https://syzkaller.appspot.com/x/.config?x=e2808e34f8becb71
dashboard link: https://syzkaller.appspot.com/bug?extid=f8495bff23a879a6d0bd
compiler:       clang version 8.0.0 (trunk 343298)
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=17c0326d400000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=17e4d45d400000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+f8495bff23a879a6d0bd@xxxxxxxxxxxxxxxxxxxxxxxxx

Local variable description: ----walk@crypto_ctr_crypt
Variable was created at:
 crypto_ctr_crypt+0xae/0xc30 crypto/ctr.c:129
 skcipher_crypt_blkcipher crypto/skcipher.c:622 [inline]
 skcipher_encrypt_blkcipher+0x232/0x340 crypto/skcipher.c:631
==================================================================
BUG: KMSAN: uninit-value in gf128mul_4k_lle+0x29e/0x310  
crypto/gf128mul.c:391
CPU: 0 PID: 8470 Comm: syz-executor696 Not tainted 4.20.0-rc2+ #88
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS  
Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x32d/0x480 lib/dump_stack.c:113
 kmsan_report+0x19f/0x300 mm/kmsan/kmsan.c:911
 __msan_warning+0x76/0xc0 mm/kmsan/kmsan_instr.c:415
 gf128mul_4k_lle+0x29e/0x310 crypto/gf128mul.c:391
 ghash_update+0x9d3/0x10e0 crypto/ghash-generic.c:75
 crypto_shash_update crypto/shash.c:103 [inline]
 shash_ahash_update+0x4de/0x600 crypto/shash.c:244
 shash_async_update+0x50/0x60 crypto/shash.c:252
 crypto_ahash_update include/crypto/hash.h:557 [inline]
 gcm_hash_update crypto/gcm.c:235 [inline]
 gcm_hash_assoc_remain_continue crypto/gcm.c:344 [inline]
 gcm_hash_assoc_continue crypto/gcm.c:375 [inline]
 gcm_hash_init_continue crypto/gcm.c:400 [inline]
 gcm_hash+0x1dbe/0x4870 crypto/gcm.c:430
 gcm_encrypt_continue crypto/gcm.c:455 [inline]
 crypto_gcm_encrypt+0x781/0xaa0 crypto/gcm.c:484
 crypto_aead_encrypt include/crypto/aead.h:364 [inline]
 tls_do_encryption net/tls/tls_sw.c:460 [inline]
 tls_push_record+0x2545/0x4290 net/tls/tls_sw.c:657
 bpf_exec_tx_verdict+0x16c0/0x1b40 net/tls/tls_sw.c:694
 tls_sw_sendmsg+0x136d/0x2a30 net/tls/tls_sw.c:949
 inet_sendmsg+0x4e9/0x800 net/ipv4/af_inet.c:798
 sock_sendmsg_nosec net/socket.c:621 [inline]
 sock_sendmsg net/socket.c:631 [inline]
 __sys_sendto+0x940/0xb80 net/socket.c:1788
 __do_sys_sendto net/socket.c:1800 [inline]
 __se_sys_sendto+0x107/0x130 net/socket.c:1796
 __x64_sys_sendto+0x6e/0x90 net/socket.c:1796
 do_syscall_64+0xcf/0x110 arch/x86/entry/common.c:291
 entry_SYSCALL_64_after_hwframe+0x63/0xe7
RIP: 0033:0x448509
Code: e8 fc e5 ff ff 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7  
48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff  
ff 0f 83 0b 01 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f9ff6aa3cd8 EFLAGS: 00000216 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00000000006f0038 RCX: 0000000000448509
RDX: 000000000039a191 RSI: 00000000200005c0 RDI: 0000000000000003
RBP: 00000000006f0030 R08: 0000000020000000 R09: 000000000000001c
R10: 0000000000000000 R11: 0000000000000216 R12: 00000000006f003c
R13: 00000000007ffc6f R14: 00007f9ff6aa49c0 R15: 00000000000003e8

Uninit was stored to memory at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:252 [inline]
 kmsan_save_stack mm/kmsan/kmsan.c:267 [inline]
 kmsan_internal_chain_origin+0x136/0x240 mm/kmsan/kmsan.c:569
 __msan_chain_origin+0x6d/0xb0 mm/kmsan/kmsan_instr.c:292
 __crypto_xor+0x224/0x15c0 crypto/algapi.c:1029
 crypto_xor include/crypto/algapi.h:219 [inline]
 ghash_update+0x991/0x10e0 crypto/ghash-generic.c:74
 crypto_shash_update crypto/shash.c:103 [inline]
 shash_ahash_update+0x4de/0x600 crypto/shash.c:244
 shash_async_update+0x50/0x60 crypto/shash.c:252
 crypto_ahash_update include/crypto/hash.h:557 [inline]
 gcm_hash_update crypto/gcm.c:235 [inline]
 gcm_hash_assoc_remain_continue crypto/gcm.c:344 [inline]
 gcm_hash_assoc_continue crypto/gcm.c:375 [inline]
 gcm_hash_init_continue crypto/gcm.c:400 [inline]
 gcm_hash+0x1dbe/0x4870 crypto/gcm.c:430
 gcm_encrypt_continue crypto/gcm.c:455 [inline]
 crypto_gcm_encrypt+0x781/0xaa0 crypto/gcm.c:484
 crypto_aead_encrypt include/crypto/aead.h:364 [inline]
 tls_do_encryption net/tls/tls_sw.c:460 [inline]
 tls_push_record+0x2545/0x4290 net/tls/tls_sw.c:657
 bpf_exec_tx_verdict+0x16c0/0x1b40 net/tls/tls_sw.c:694
 tls_sw_sendmsg+0x136d/0x2a30 net/tls/tls_sw.c:949
 inet_sendmsg+0x4e9/0x800 net/ipv4/af_inet.c:798
 sock_sendmsg_nosec net/socket.c:621 [inline]
 sock_sendmsg net/socket.c:631 [inline]
 __sys_sendto+0x940/0xb80 net/socket.c:1788
 __do_sys_sendto net/socket.c:1800 [inline]
 __se_sys_sendto+0x107/0x130 net/socket.c:1796
 __x64_sys_sendto+0x6e/0x90 net/socket.c:1796
 do_syscall_64+0xcf/0x110 arch/x86/entry/common.c:291
 entry_SYSCALL_64_after_hwframe+0x63/0xe7

Uninit was stored to memory at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:252 [inline]
 kmsan_save_stack mm/kmsan/kmsan.c:267 [inline]
 kmsan_internal_chain_origin+0x136/0x240 mm/kmsan/kmsan.c:569
 __msan_chain_origin+0x6d/0xb0 mm/kmsan/kmsan_instr.c:292
 __crypto_xor+0x224/0x15c0 crypto/algapi.c:1029
 crypto_xor include/crypto/algapi.h:219 [inline]
 crypto_ctr_crypt_inplace crypto/ctr.c:115 [inline]
 crypto_ctr_crypt+0x776/0xc30 crypto/ctr.c:142
 skcipher_crypt_blkcipher crypto/skcipher.c:622 [inline]
 skcipher_encrypt_blkcipher+0x232/0x340 crypto/skcipher.c:631
 crypto_skcipher_encrypt include/crypto/skcipher.h:534 [inline]
 crypto_gcm_encrypt+0x512/0xaa0 crypto/gcm.c:483
 crypto_aead_encrypt include/crypto/aead.h:364 [inline]
 tls_do_encryption net/tls/tls_sw.c:460 [inline]
 tls_push_record+0x2545/0x4290 net/tls/tls_sw.c:657
 bpf_exec_tx_verdict+0x16c0/0x1b40 net/tls/tls_sw.c:694
 tls_sw_sendmsg+0x136d/0x2a30 net/tls/tls_sw.c:949
 inet_sendmsg+0x4e9/0x800 net/ipv4/af_inet.c:798
 sock_sendmsg_nosec net/socket.c:621 [inline]
 sock_sendmsg net/socket.c:631 [inline]
 __sys_sendto+0x940/0xb80 net/socket.c:1788
 __do_sys_sendto net/socket.c:1800 [inline]
 __se_sys_sendto+0x107/0x130 net/socket.c:1796
 __x64_sys_sendto+0x6e/0x90 net/socket.c:1796
 do_syscall_64+0xcf/0x110 arch/x86/entry/common.c:291
 entry_SYSCALL_64_after_hwframe+0x63/0xe7

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:252 [inline]
 kmsan_internal_alloc_meta_for_pages+0x155/0x740 mm/kmsan/kmsan.c:689
 kmsan_alloc_page+0x77/0xc0 mm/kmsan/kmsan_hooks.c:320
 __alloc_pages_nodemask+0x12ac/0x64d0 mm/page_alloc.c:4421
 alloc_pages_current+0x55d/0x7d0 mm/mempolicy.c:2080
 alloc_pages include/linux/gfp.h:511 [inline]
 skb_page_frag_refill+0x48e/0x7a0 net/core/sock.c:2213
 sk_page_frag_refill+0xa4/0x330 net/core/sock.c:2233
 sk_msg_alloc+0x22f/0x11a0 net/core/skmsg.c:37
 tls_alloc_encrypted_msg net/tls/tls_sw.c:236 [inline]
 tls_sw_sendmsg+0xd0c/0x2a30 net/tls/tls_sw.c:871
 inet_sendmsg+0x4e9/0x800 net/ipv4/af_inet.c:798
 sock_sendmsg_nosec net/socket.c:621 [inline]
 sock_sendmsg net/socket.c:631 [inline]
 __sys_sendto+0x940/0xb80 net/socket.c:1788
 __do_sys_sendto net/socket.c:1800 [inline]
 __se_sys_sendto+0x107/0x130 net/socket.c:1796
 __x64_sys_sendto+0x6e/0x90 net/socket.c:1796
 do_syscall_64+0xcf/0x110 arch/x86/entry/common.c:291
 entry_SYSCALL_64_after_hwframe+0x63/0xe7
==================================================================


---
This bug is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxxx

syzbot will keep track of this bug report. See:
https://goo.gl/tpsmEJ#bug-status-tracking for how to communicate with  
syzbot.
syzbot can test patches for this bug, for details see:
https://goo.gl/tpsmEJ#testing-patches